BACKGROUND: Wnt signaling plays important roles in neurodevelopmental processes. Frizzled is a receptor of Wnt protein, and the Frizzled 3 (FZD3) gene was recently reported to be associated with schizophrenia. Our study attempted to confirm associations between FZD3 and schizophrenia in Japanese family and case-control samples. METHODS: Genetic associations were evaluated using family-based transmission tests (212 families, 643 subjects) and case--control analysis (540 schizophrenia patients, 540 control sample). Six single nucleotide polymorphisms (SNPs) on the FZD3 locus were genotyped, and levels of FZD3 mRNA expression in postmortem brains were examined. RESULTS: Neither family- nor population-based studies supported associations between FZD3 and schizophrenia. FZD3 expression was unaltered in schizophrenic brains. CONCLUSIONS: Although two prior studies have reported associations using limited numbers of SNPs on FZD3, our intensive study failed to support any major contribution of FZD3 to schizophrenia susceptibility.
BACKGROUND: Wnt signaling plays important roles in neurodevelopmental processes. Frizzled is a receptor of Wnt protein, and the Frizzled 3 (FZD3) gene was recently reported to be associated with schizophrenia. Our study attempted to confirm associations between FZD3 and schizophrenia in Japanese family and case-control samples. METHODS: Genetic associations were evaluated using family-based transmission tests (212 families, 643 subjects) and case--control analysis (540 schizophreniapatients, 540 control sample). Six single nucleotide polymorphisms (SNPs) on the FZD3 locus were genotyped, and levels of FZD3 mRNA expression in postmortem brains were examined. RESULTS: Neither family- nor population-based studies supported associations between FZD3 and schizophrenia. FZD3 expression was unaltered in schizophrenic brains. CONCLUSIONS: Although two prior studies have reported associations using limited numbers of SNPs on FZD3, our intensive study failed to support any major contribution of FZD3 to schizophrenia susceptibility.